U.S. patent number 4,624,690 [Application Number 06/750,335] was granted by the patent office on 1986-11-25 for apparatus for removing particulates.
This patent grant is currently assigned to Markel Industries, Inc.. Invention is credited to John Byrnes.
United States Patent |
4,624,690 |
Byrnes |
November 25, 1986 |
Apparatus for removing particulates
Abstract
An apparatus for removing particulates from objects comprises a
cleaning chamber which is open on at least one side to receive the
object, a curtain of air which covers the opening to the cleaning
chamber, and two converging air streams within the cleaning
chamber, which converging air streams create turbulence in the
vicinity of the object and dislodge particulates from it. The air
curtain acts as a barrier to prevent such dislodged particulates
from escaping into the surrounding environment. The air streams and
the air curtain are recirculated and HEPA filtered to trap the
dislodged particulates.
Inventors: |
Byrnes; John (Lebanon, CT) |
Assignee: |
Markel Industries, Inc.
(Enfield, CT)
|
Family
ID: |
25017437 |
Appl.
No.: |
06/750,335 |
Filed: |
June 28, 1985 |
Current U.S.
Class: |
55/385.1;
15/316.1; 55/DIG.29 |
Current CPC
Class: |
B01D
50/002 (20130101); B08B 15/023 (20130101); B08B
5/023 (20130101); Y10S 55/29 (20130101) |
Current International
Class: |
B01D
50/00 (20060101); B08B 15/00 (20060101); B08B
15/02 (20060101); B08B 5/02 (20060101); B01D
050/00 () |
Field of
Search: |
;55/302,DIG.29,385R,473
;15/310,346,316R ;134/56R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hart; Charles
Attorney, Agent or Firm: McCormick, Paulding & Huber
Claims
I claim:
1. An apparatus for removing particulates from an object, said
apparatus comprising:
means defining a cleaning chamber for receiving an object and
having a constantly open opening allowing an object to be moved at
all times freely between said chamber and the external environment
surrounding said chamber,
means for developing a first stream of air within said cleaning
chamber to remove particulates from an object when received within
said cleaning chamber,
means for developing a curtain of air within said chamber which
curtain of air is located adjacent said opening and flows across
said opening generally in a plane parallel to said opening to cover
said opening and to thereby inhibit particulates removed from an
object by said first stream from escaping from said cleaning
chamber through said opening, and
means for recirculating the air of said curtain and the air of said
first stream.
2. An apparatus as set forth in claim 1 further comprising means
for filtering the air of said curtain and the air of said first
stream to remove particulates having a diameter 0.3 microns and
larger.
3. An apparatus as set forth in claim 2 wherein said means for
filtering comprises a high efficiency particulate filter.
4. An apparatus as set forth in claim 3 further comprising means
for developing a second stream of air within said cleaning chamber
to clean particulates from an object, said first and seocnd steams
of air converging upon one another at a first cleaning zone and
causing turbulence.
5. An apparatus as set forth in claim 4 further comprising means
for automatically turning on said first and second streams of air
and said curtain of air in response to the presence of an object in
said cleaning chamber.
6. An apparatus as set forth in claim 5 further comprising means
for turning off said first and second steams of air and an curtain
of air at least one second after said object is withdrawn from said
cleaning chamber.
7. An apparatus as set forth in claim 5 wherein said means for
automatically turning on said first and second streams of air and
said curtain of air includes an electric eye for detecting the
presence of an object in said cleaning chamber.
8. An apparatus as set forth in claim 4 wherein said means for
developing said first stream of air includes means for directing it
generally parallel to said curtain of air, and wherein said means
for developing said second steam of air includes means for
directing it generally parallel to said curtain of air.
9. An apparatus as set forth in claim 8 wherein
said means for recirculating the air of said first stream, said
second stream, and said curtain comprises a return air chase having
an entrance, and
said means for developing said first stream of air, said means for
developing said second stream of air, and said means for developing
said curtain of air are located on one side of said cleaning
chamber, and said entrance of said return air chase is located on
an opposite side of said cleaning chamber.
10. An apparatus as set forth in claim 4 further comprising:
means for developing a third stream of air within said cleaning
chamber for cleaning another object, and
means for developing a fourth stream of air within said cleaning
chamber for cleaning said other object, said third and fourth
streams of air converging upon one another at a second cleaning
zone spaced from said first cleaning zone.
11. An apparatus as set forth in claim 3 further comprising means
for heating a thermoplastic glove while located within said
cleaning chamber to a temperature sufficient to trap particulates
located on the surface of said glove.
12. An apparatus as set forth in claim 11 for use with heat
shrinkable thermoplastic gloves and wherein said means for heating
a thermoplastic glove is capable of heating such a glove to a
temperature sufficient to cause it to shrink.
13. An apparatus as set forth in claim 3 wherein said opening is
the only opening through which an object may be moved into and out
of said cleaning chamber for cleaning.
14. An apparatus as set forth in claim 1 further comprising means
for illuminating said cleaning chamber with black light.
15. An apparatus as set forth in claim 1 further comprising means
for agitating an object within said cleaning chamber to facilitate
the removal of particulates.
16. An apparatus as set forth in claim 15 further comprising means
for filtering the air of said curtain and the air of said first
stream to remove particulates having a diameter 0.3 microns and
larger.
17. An apparatus as set forth in claim 1 wherein said means for
developing said first stream of air includes means for directing it
generally parallel to said curtain of air.
18. An apparatus as set forth in claim 1 for use in cleaning a
person's foot and wherein said means defining said cleaning chamber
includes a vertical front wall having an upper horizonal edge and a
horizontal top wall extending rearwardly from said upper horizontal
edge of said front wall, said opening being in said front wall and
said top wall having a rearwardly extending mouth merging with said
opening at said upper edge of said front wall, said opening and
mouth being of such size and shape as to accommodate a person's
foot and the adjacent portion of the person's foreleg, said mouth
having a roudned rear boundary to generally mate with a person's
foreleg.
19. A system for removing particulates from an object, said system
comprising:
means defining a cleaning chamber having first and second opposite
sides and having a first constantly open window on said first side
and a second constantly open window on said second side,
means for developing a first stream of air within said cleaning
chamber to remove particulates from an object when received within
said cleaning chamber,
means for developing a first curtain of air within said chamber
which curtain of air is located adjacent said first window and
flows across said first window generally in a plane parallel to
said first window to cover said first window to inhibit
particulates removed from an object by said first stream from
escaping from said cleaning chamber while nevertheless allowing an
object to be moved freely through said first window between said
cleaning chamber and the external environment surrounding said
chamber
means for developing a second curtain of air within said chamber
which curtain of air is located adjacent said second window and
flows across said second window generally in a plane parallel to
said first window to cover said second window to inhibit
particulates removed from an object by said first stream from
escaping from said cleaning chamber while nevertheless allowing an
object to be moved freely through said second window between said
cleaning chamber and the external environment surrounding said
chamber, and
means for moving an object into said cleaning chamber through said
first window, through said cleaning chamber, and then out of said
cleaning chamber through said second window.
20. A system as set forth in claim 19 further comprising
means for recirculating the air of said first curtain, the air of
said second curtain and the air of said first air stream, and
means for filtering the recirculated air to remove
particulates.
21. A system as set forth in claim 20 wherein said means for
filtering comprises a high efficiency particulate filter.
22. A system as set forth in claim 20 further comprising means for
developing a second stream of air within said cleaning chamber,
said second stream of air converging upon said first stream of air
at a cleaning zone located within said cleaning chamber.
23. A system as set forth in claim 21 further comprising means for
controlling the movement of said object through said first window,
said cleaning chamber and said second window and for controlling
said first curtain of air, said second curtain of air and said
first stream of air such that said first curtain of air, said
second curtain of air and said first stream of air are turned off
while said object enters said cleaning chamber and turned on after
said object is fully received within said cleaning chamber.
24. A system as set forth in claim 23 wherein said means for moving
said object comprises an endless, moving conveyor.
25. An apparatus for removing particulates from the surface of an
object, said apparatus comprising:
means defining a cleaning chamber to receive an object, said
cleaning chamber having a constantly open opening allowing an
object to be moved at all times freely between said chamber and the
external environment surrounding said chamber,
means for developing a first stream of air within said cleaning
chamber, said first stream of air being aimed at a cleaning zone
within said cleaning chamber to remove particulates from an object
when said object is located in said cleaning zone,
means for developing a second stream of air within said cleaning
chamber, said second stream of air being aimed at said cleaning
zone and intersecting said first stream of air in the vicinity of
said cleaning zone causing turbulence,
means for recirculating the air of said first stream and the air of
said second stream, and
means for filtering the recirculated air to remove particulates,
said means for filtering comprising a high efficiency particulate
filter.
26. An apparatus as set forth in claim 25 wherein said first stream
of air is directed generally parallel to said opening and said
second stream of air is directed generally parallel to said
opening.
27. An apparatus as set forth in claim 25 further comprising means
for developing a curtain of air within said chamber which curtain
of air is located ajdacent said opening and flows across said
opening generally in a plane parallel to said opening to cover said
opening and to thereby inhibit particulates removed from an object
by said first and second stream from escaping from said chamber
through said opening, the air of said curtain being recirculated by
said means for recirculating the air of said first stream and the
air of said second stream, and being filtered by said means for
filtering the recircualted air.
28. An apparatus for removing particulates from a person's gloved
hand, said apparatus comprising:
means defining a cleaning chamber to receive a person's gloved hand
while excluding said person's torso, said cleaning chamber having a
constantly open opening through which a person's hand gloved by a
glove unattached to said chamber defining means may be moved at all
times freely between said cleaning chamber and the external
environment surrounding said chamber,
means for developing at least one stream of air within said
cleaning chamber to remove particulates from said gloved hand when
received within said cleaning chamber,
means for recirculating the air of said first stream, and
means for filtering the recirculated air to remove
particulates.
29. An apparatus as set forth in claim 28 wherein said means for
filtering comprises a high efficiency particulate filter which is
capable of removing particulates approximately 0.3 microns in
diameter.
30. An apparatus as set forth in claim 29 further comprising means
for developing a curtain of air within said chamber which curtain
of air is located adjacent said opening and flows across said
opening generally in a plane parallel to said opening to cover said
opening and to thereby inhibit particulates removed from a gloved
hand from escaping from said cleaning chamber, the air of said
curtain being recirculated and being filtered by said means for
filtering.
31. An apparatus as set forth in claim 30 further comprising means
for developing a second stream of air within said cleaning chamber
to clean particulates from a gloved hand, said first and second
streams of air converging upon one another at a cleaning zone and
causing turbulence.
32. An apparatus as set forth in claim 31 wherein said apparatus is
small enough to fit on a desk top.
33. An apparatus as set forth in claim 28 wherein said apparatus is
small enough to fit on a desk top.
34. An apparatus as set forth in claim 28 further comprising means
for actuating said means for developing at least one stream of air
in response to the presence of an object in said cleaning
chamber.
35. An apparatus as set forth in claim 34 further comprising means
for turning off said at least one stream of air at least one second
after an object is withdrawn from said cleaning chamber.
36. An apparatus as set forth in claim 35 wherein said means for
activating said at least one stream of air includes a photoelectric
eye positioned to sense the presence of an object within said
cleaning chamber.
37. An apparatus for removing particulates from objects, said
apparatus comprising:
means defining a cleaning chamber which is large enough to receive
a person's hand but small enough to exclude the torso of said
person, said cleaning chamber having a constantly open opening on
at least one side allowing an object to be moved by a person's hand
at all times freely between said chamber and the external
environment surrounding said chamber,
means for developing a first stream of air within said cleaning
chamber to remove particulates from an object when received within
said cleaning chamber and held by a person's hand,
means for receiving the air of said first stream and particulates
removed from an object by the air of said first stream, and
means for preventing the removed particulates from escaping into
the environment surrounding said apparatus.
38. An apparatus as set forth in claim 37 wherein said means for
receiving the air of said first stream and preventing the removed
particulates from escaping comprises a filter which is capable of
removing particulates less than 1.0 micron in diameter.
39. An apparatus as set forth in claim 37 further comprising means
for developing a second stream of air within said cleaning chamber
clean particulates from said object, said first and second streams
of air converging upon one another at a cleaning zone and causing
turbulence.
40. An apparatus for removing particulates from objects, said
apparatus comprising:
means for defining a cleaning chamber which is large enough to
receive a person's hand but small enough to exclude the remainder
of said person, said cleaning chamber having a constantly open
opening on a first side allowing an object to be moved by a
person's hand at all times freely between said chamber and the
external environment surrounding said chamber,
means for developing a first flow of air within said cleaning
chamber to remove particulates from an object when received within
said cleaning chamber,
means for receiving the air of said first flow and particulates
removed from an object and entrained by the air of said first flow,
and
means for preventing the removed particulates from escaping into
the environment surrounding said apparatus.
41. An apparatus as set forth in claim 40 wherein said means for
receiving the air of said first flow and preventing the removed
particulates from escaping comprises means for filtering the
received air.
42. An apparatus as set forth in claim 41 wherein said means for
receiving the air of said first flow and preventing the removed
particulates from escaping further comprises means for developing a
curtain of air within said chamber which curtain of air is located
adjacent said opening and flows across said opening generally in a
plane parallel to said opening to cover said opening and to thereby
inhibit particulates removed from an object from escaping from said
cleaning chamber, the air of said curtain being recirculated and
being filtered by said means for filtering.
43. An apparatus as set forth in claim 42 further comprising means
for developing a second flow of air within said cleaning chamber to
clean particulates from an object, said first and second flows of
air converging upon one another causing turbulence.
Description
BACKGROUND OF THE INVENTION
The invention relates generally to apparatuses for removing
particulates from objects and deals more particularly with
apparatuses which remove particulates from gloved hands, clad feet,
wipes and other objects by use of an air stream, and prevents the
removed particulates from re-entering the surrounding
environment.
Apparatuses of the general type with which this invention is
concerned are used in conjunction with clean rooms such as
semiconductor and pharmaceutical fabrication rooms, hospital
operating rooms, certain laboratories any other rooms where it is
important to provide an environment which is very low in
particulates such as dirt, dust, skin cells and bacteria. In such
rooms, workers often wear gloves and booties to prevent such
particulates on their hands and feet from contaminating objects
which the worker touches and to prevent such particulates from
being shaken into the air from their hands and feet and randomly
contaminating other objects in the room.
A worker often begins a work day with a relatively clean pair of
gloves and booties which he or she removes directly from sealed
packages in a clean room. However, in removing the gloves and
booties, some particulates from within the packages escape into the
clean room and in donning the gloves and booties, the worker
invariably touches exterior surfaces of them with his or her hands
and thereby contaminates such exterior surfaces. Also, during the
course of a workday, the worker often touches his or her hands to
exposed portions of his or her face and to other relatively dirty
objects and thereby, contaminates the gloves further, and often
brushes his or her feet against dirty furniture and steps on dirty
portions of the floor and thereby contaminates the booties
further.
Presently, it is common for workers to change their gloves and
booties during the course of a workday and discard the
contaminated, old ones. Also, there are air showers located
adjacent or within some clean rooms to clean particulates from a
person, which air showers typically comprise a small enclosed
shower room having an entrance door and an exit door, and blowers
which produce air streams within the shower room. The blowers force
air through apertures in the walls and ceilings of the shower room
and return the air through other apertures usually in the floor.
High efficiency air particulate (HEPA) filters are also provided to
cleanse the air returned from the shower room, such filters being
effective in trapping particulates 0.3 microns in diameter and
larger.
The apertures in one type of shower room take the form of a pair of
coplanar slots located in opposing walls, and extending vertically
from a point a few feet high to a point approximately five feet
high. To correctly utilize this type of air shower, a worker opens
the entrance door, enters the shower room, positions himself or
herself between the slots, raises his or her arms and turns in a
complete circle. The blower forces a stream of generally laminar
air through each slot, into the shower room and against the person
to dislodge particles from the person's body. Some of the
particulates are immediately entrained in the return flow of air
and drawn through the floor and the filter, and other of the
dislodged particulates float into the air within the shower room,
are contained by the walls and ceiling of the shower room and most
are eventually entrained in the return flow of air and filtered.
However, some of these other particulates may escape from the
shower room when the worker exits.
Another similar type of air shower uses a group of nozzles located
on the ceiling and walls of the associated shower room instead of
the vertical slots to direct streams of air against a user.
Air showers of the types described above are general purpose
apparatuses for cleaning one's body and do not concentrate on the
hands and feet which, as discussed above, are particular sources of
repeated contamination. Also, the shower rooms take up many square
feet of floor space and the process of utilizing the air showers,
from the time the user opens the entrance door to the time the
worker exits the shower room, usually requires 30 seconds or more
and is inconvenient. Furthermore, the doors of the type of air
shower room discussed above are opened manually with handles, which
handles provide a source of contamination.
Cleaning and heat-shrinking apparatuses for thermoplastic gloves
are presently known which comprise a blower, a high-efficiency
particulate filter located between the blower and the object to be
cleaned, and a heater to heat the blown air before it reaches the
object. The hot air shrinks gloves worn by a user to improve their
fit, trap particulates, and dislodge particulates from the gloves.
However, the air blown by the blower is not recirculated and no air
curtain is provided to block the dislodged particulates so that the
dislodged particulates enter the surrounding environment.
Consequently, such a device is usually installed outside of a clean
room.
There are other objects used in clean rooms which are contaminated
with particulates and require cleaning, for example, parts used to
fabricate a product and wipes used to clean furniture, equipment
and such fabrication parts. Presently, the wipes are discarded
after use.
Accordingly, a general aim of the invention is to provide a
cleaning apparatus which effectively removes particulates from
objects such as gloved hands, clad feet, wipes and fabrication
parts and prevents the particulates from re-entering a
workroom.
Another general aim of the invention is to provide a cleaning
apparatus of the foregoing type which removes the particulates
quickly with minimal inconvenience to the user.
A more specific aim of the invention is to provide apparatuses of
the foregoing types which are more compact than a conventional air
shower and concentrate their cleaning efforts on objects which are
small compared to a worker's entire body.
Another specific aim of the invention is to provide cleaning
apparatuses of the foregoing types which remove particulates 0.3
microns in diameter and larger.
Still another specific aim of the invention is to provide a
cleaning system which is specially adapted to remove particulates
from large quantities of wipes.
Other aims of the invention will become apparent from the following
detailed descriptions and drawings.
SUMMARY OF THE INVENTION
The invention resides in an apparatus for removing particulates
from an object, which apparatus comprises a cleaning chamber which
is open on at least one side and receives the object and means for
developing a stream of air within the cleaning chamber to remove
particulates from the object. According to one feature of the
invention, the apparatus further comprises means for developing a
curtain of air which covers the opening to the cleaning chamber,
the curtain of air preventing such removed particulates from
escaping from the cleaning apparatus into the surrounding
environment. According to another feature of the invention, the
apparatus includes means for developing a second stream of air
within the cleaning chamber to remove particulates from the object,
the second stream of air converging upon the first stream of air in
the vicinity of the object causing turbulence, which turbulence
facilitates the removal of particulates from the object.
According to another feature of the invention, means are provided
within the cleaning chamber to agitate wipes, loose gloves and
loose booties, and other limp objects and, according to still
another feature of the invention, conveyor means are provided to
carry wipes and other such limp objects into and out of a cleaning
chamber to automate the cleaning process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cleaning apparatus embodying the
invention.
FIG. 2 is a side sectional view of the cleaning apparatus of FIG.
1.
FIG. 3 is a front sectional view of the cleaning apparatus of FIG.
1 taken along the plane 3,3.
FIG. 4 is a rear sectional view of the cleaning apparatus of FIG. 1
taken along the plane 4,4.
FIG. 5 is a perspective view of channels which develop air streams
and air curtains within the cleaning apparatus of FIG. 1.
FIG. 6 is a schematic, block diagram of a photoelectric eye and a
delaying circuit used to control a blower within the cleaning
apparatus of FIG. 1.
FIG. 7 is a perspective view of another cleaning apparatus
embodying the invention.
FIG. 8 is a side sectional view of the cleaning apparatus of FIG.
7.
FIG. 9 is a front sectional view of the cleaning apparatus of FIG.
7 taken along the plane 9,9.
FIG. 10 is a perspective view of another cleaning apparatus
embodying the invention.
FIG. 11 is a top sectional view of the cleaning apparatus of FIG.
10.
FIG. 12 is a front sectional view of the cleaning apparatus of FIG.
10 taken along the plane 12,12.
FIG. 13 is a perspective view of the interior construction of the
cleaning apparatus of FIG. 10.
FIG. 14 is a perspective view of a particulate cleaning system
embodying the invention.
FIG. 15 is a front sectional view of a particulate cleaning
apparatus within the particulate cleaning system of FIG. 14.
FIG. 16 is a side sectional view of the particulate cleaning
apparatus within the particulate cleaning system of FIG. 14 taken
along the plane 16,16.
FIG. 17 is a perspective view of another particulate cleaning
apparatus embodying the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, FIG. 1 shows a particulate cleaning
apparatus generally designated 10 which embodies the present
invention. The apparatus 10 is generally box-shaped and small
enough, for example, 2'.times.2'.times.2' to fit on a desk top. It
has a cleaning chamber 12 with a window opening 13 at the front to
receive an object such as a person's gloved hands 14,14 (as shown),
handheld parts or parts placed within the chamber. The cleaning
chamber 12 and the window opening 13 are also large enough to allow
a user to insert both hands and a package of gloves, open the
package and don the gloves. Arrows 16,16 are inscribed on the box
to indicate the proper placement of the hands or other objects
within the cleaning chamber 12 for cleaning purposes. In general,
air is forced downwardly from a portion 18 of the apparatus 10
which defines an upper limit to the cleaning chamber 12 and is
returned via a portion 19 of the apparatus 10 which defines a lower
limit to the cleaning chamber.
As shown more clearly in FIGS. 2 and 3, the apparatus 10 includes a
blower 24 located in a rear chamber 23, a diffuser 26 located above
the blower, a HEPA filter 28 located above the diffuser and spaced
a few inches therefrom, an air delivery plenum 30 leading forwardly
from the HEPA filter, tapered channels 32, 34, 60, 62 and 64 which
direct and accelerate air from the air delivery plenum into the
cleaning chamber 12, and an air return chase 36 leading back to the
blower 24.
By way of example, the blower 24 is rated at one-fifth horsepower
and 1000 cubic feet per minute of air when unimpaired and 550 cubic
feet per minute when impaired to the extent of a one inch of
mercury static pressure differential. The mouth of the blower 24
abuts a divider 38 having an aperture above the mouth, and the
diffuser 26 is supported on the other side of the divider 28
adjacent the mouth of the blower. The diffuser has a conventional
design and includes apertures which disperse the blown air against
much of the underside of the HEPA filter 28. The filter 28 is
mounted to a rectangular filter frame 40, comprises woven fibers
and, by way of example, is two feet long, one foot wide and 3-1/4
inches thick and causes a one inch of mercury static pressure
differential between its two faces. By way of example, the HEPA
filter 28 is rated to trap particulates 0.3 microns in diameter and
larger, but finer HEPA filters are available, ones which trap
particulates down to 0.1 microns. The finer the HEPA filter the
better the performance of the apparatus 10; however, the higher the
cost. It is presumed that as technology progresses, HEPA filters
will be available at reasonable cost which trap smaller and smaller
particulates.
Air proceeds upwardly from the filter 28 at a speed greater than
100 feet per minute. Then, the air proceeds forwardly through a
forward portion 42 of the air delivery plenum 30 as indicated by an
arrow 41, and is accelerated because the forward portion 42 has a
smaller cross sectional area than the face of the filter 28, the
cross sectional area of the forward portion 42 being that in the
vertical plane. Next, some of the blown air proceeds through the
channel 32 which channel extends laterally from a left wall 50 to a
right wall 52 of the apparatus 10 and tapers vertically, by way of
example, from a three inch width to a one-fourth inch width. (See
FIG. 2) The speed of the air increases through the tapered channel
to approximately 600 feet per minute and proceeds downwardly as a
curtain of air 51, as indicated by arrows 49,49, which curtain
completely covers the front window opening 13 of the cleaning
chamber 12 and acts as a barrier between the cleaning chamber and
the rest of the clean room. The curtain of air 51 proceeds through
perforations in a metal sheet 54 at the bottom of the cleaning
chamber and into the air return chase 36.
As shown in FIGS. 3 and 5, the channel 34 is formed by a panel or
wall 68 which is vertical and a panel or wall 66 which angles away
from the side wall 52, and the channel 60 is formed by a panel or
wall 70 which is vertical and a panel or wall 72 which angles
towards the side wall 52. Both channels communicate with the air
delivery plenum 30 by openings 91 and 93 at the top and with the
cleaning chamber 12 by openings 95 and 97 respectively at the
bottom. By way of example, the top openings 91 and 93 are three
inches wide and the bottom openings 95 and 97 are one-fourth inch
wide. Because of the dimension of the channels 34 and 60, air
accelerates from the air delivery plenum 30 through the channels 34
and 60 to approximately 600 feet per second. Each of the channels
34 and 60 extends front-to-back from a point directly behind the
air curtain 51 to the rearward limit of the cleaning chamber 12.
Hence, as indicated by arrows 74,74, the channel 34 develops a wide
stream of air, initially laminar, which proceeds straight
downwardly, laterally inwardly of the cleaning chamber 12, parallel
to the air curtain 51 and towards a cleaning zone occupied by the
right hand 14 indicated as a. As indicated by arrows 76,76, the
channel 60 develops a wide stream of air, initially laminar, which
proceeds downwardly, laterally outwardly of the cleaning chamber,
parallel to the air curtain 51, towards a cleaning zone occupied by
the hand 14a and towards the stream of air developed by the channel
34. Hence, the two streams of air converge upon the hand 14a and
upon one another in the vicinity of the hand 14a and thereby cause
each other's air flows to become turbulent.
Similarly, the channel 62 is defined by a panel or wall 82 which is
vertical and a panel or wall 80 which angles towards the side wall
50, and the channel 64 is defined by a panel or wall 86 which is
vertical and a panel or wall 84 which angles away from the side
wall 50. Both of the channels 62 and 64 communicate with the air
delivery plenum 30 by openings 101 and 103 at the top and with the
cleaning chamber 12 by openings 102 and 104, respectively, at the
bottom. By way of example, the top openings 101 and 103 are three
inches wide and the bottom openings 102 and 104 are one-fourth inch
wide. The walls 80, 82, 84 and 86 extend from a point directly
behind the air curtain 51 to the rearward limit of the cleaning
chamber 12 and therefore develop two relatively wide streams of
air, initially laminar, which proceed straight downwardly parallel
to the air curtains 51, and as indicated by arrows 90,90 and 92,92,
converge upon the left hand 14 indicated as b and upon one another.
The two intersecting air streams from the channels 62 and 64 cause
turbulent air to flow against and flow in the vicinity of the hand
14b.
It is believed that the turbulence in the air created by the
intersection of the air streams from the channels 34 and 60 at the
surface of the gloved hand 14a and from the channels 62 and 64 at
the surface of the gloved hand 14b facilitates the breaking of
surface bonds between particulates located on the gloves and the
gloves themselves and the lifting of particulates from the gloves
and therefore facilitates the removal of particulates from the
gloves or other objects similarly situated. Movement of the hands
within the cleaning chamber also facilitates the removal of
particulates from the gloves. Most of the removed particulates are
immediately entrained in the return air flow of the air streams of
the channels 34, 60, 62, and 64 and drawn downwardly through the
perforations in the sheet 54, into the air return chase 36 and back
into the blower 24 and then forced into the HEPA filter 28 where
they are trapped. However, some of the freed particulates may
initially avoid the return air flow and float for a short time
within the cleaning chamber 12. Some of the avoiding particulates
may migrate towards the front window opening 13 of the cleaning
chamber 12, in which case they are entrained by the air curtain 51,
and drawn downwardly into the air return chase 36 and forced into
the HEPA filter 28. The other particulates which initially avoid
the return air flow of the channels 34, 60, 62, and 64 are
eventually returned by them.
As shown schematically in FIGS. 1 and 3, photoelectric eyes 90,90
are installed within the cleaning apparatus 10 to activate the
blower 24. Each electric eye 90 includes a photo emitter 92 and a
photosensor 94 in the path of light emitted by the photo emitter.
The photo emitter 92 indicated as a is supported on the perforated
sheet 54 approximately halfway into the chamber 12 directly beneath
the line of intersection of the air streams developed by the
channels 62 and 64, and the associated photo sensor 94 indicated as
a is supported on the underside of the upper portion 18 directly
above the photo emitter 92a. Similarly, the photo emitter 92
indicated as b is supported on the perforated sheet 54
approximately halfway into the cleaning chamber 12 directly below
the line of intersection of the air streams developed by the
channels 62 and 64, and the associated photo sensor 94 indicated as
b is supported on the underside of the upper portion 18 directly
above the photo emitter 92b. Hence, when an object is located well
within the cleaning chamber 12 at either cleaning position, the
respective photoelectric eye 90 is activated.
Because the electric eyes 90,90 are located approximately half the
way into the cleaning chamber 12, the blower is not activated until
the contaminated object, either the gloved hand or other object is
well within the cleaning chamber 12 and behind the air curtain 51.
Consequently, particulates which are dislodged from the
contaminated object cannot escape into the workroom. If the blower
24 was instead activated while the gloved hands or other objects
were being inserted, then some particulates may be dislodged by the
air curtain 51, avoid the return air flow of the air curtain and
float into the workroom. The use of the electric eyes also saves
energy.
As illustrated schematically by FIG. 6, an OFF-delay timing circuit
96 is provided to allow the blower 24 to remain on for one or more
seconds after the hand 14 or other object is removed the path of
either electric eye 90. This delay allows the apparatus 10 to purge
the cleaning chamber 12 of particulates once the hand 14 or other
object is withdrawn so that any particulates freed from the glove
or other object at the time of withdrawal or shortly before, remain
behind the air curtain 51 and do not escape into the work room.
As shown in FIGS. 1 and 3, a heating coil 187 is included within
the cleaning chamber 12, which heating coil is an optional feature
of the apparatus 10. It is used to heat and thereby shrink
thermoplastic gloves worn by a person, which shrinkage improves the
fit of the gloves and traps particulates located on their surface.
By way of example, the heating coil delivers 600 watts of heat and
is turned on at the onset of a workday and for a short time after a
lunch hour to treat newly donned gloves.
FIGS. 7 through 10 illustrate another embodiment of the invention
generally designated 210, which embodiment is similar to the
cleaning apparatus 10 except that the apparatus 210 is
approximately one-half the size. Essentially, the cleaning
apparatus 210 is the same as the right half of the cleaning
apparatus 10 except that the apparatus 210 includes a blower 224 in
place of the blower 24, the blower 224 having half the power. Also,
the apparatus 224 is operated in a similar fashion to that of the
apparatus 10 except that the apparatus 224 is designed to
accommodate only one hand 14 at a time, objects held by the one
hand, or a lesser amount of objects placed within the cleaning
chamber.
Air blown by the blower 224 passes through perforations in a sheet
227, an air disperser 226, a HEPA filter 228, an air delivery
plenum 230, tapered channels 232, 234 and 260, a cleaning chamber
212, perforations in a sheet 254, and a return air chase 236.
Because of the half size of the cleaning apparatus 210, the HEPA
filter 228 is smaller, for example, 2'.times.1'.times.3 1/4", and
the length of the channel 232 is approximately half that of the
channel 32. The length of the channel 234 is the same as that of
the channel 260 and is the same as those of the channels 34 and 60,
and the widths of the air delivery chase 230 and the air return
chase 236 are approximately half those of the air delivery plenum
30 and the air return chase 36, respectively. As shown in FIG. 9,
the cleaning apparatus 210 includes only one pair of intersecting
air streams, those developed by the channels 234 and 260.
As shown in FIG. 7, the cleaning apparatus 210 also includes a lamp
271 which radiates black light into the cleaning chamber 212, which
black light exposes particulates to the naked eye. The purpose of
the black light is to inform the user when his or her gloves or
other objects contained within the cleaning chamber 212 are clean
and to motivate workers to use the cleaning apparatus 210; if they
can see particles being removed, they will be more apt to utilize
it.
FIG. 10 illustrates another embodiment of the invention generally
designated 110, which embodiment is adapted to accommodate and
clean particulates from feet, typically clad with disposable
booties or slippers. The booties or slippers may be contaminated by
their removal from a package and the donning of them or from
subsequent contact with the floor, furniture and other sources of
particulates.
More specifically, the apparatus 110 comprises a cleaning chamber
112 in which a foot 114 clad with a bootie 111 is inserted. The
cleaning chamber 112 has a rectangular window opening 156 in the
front and a "U" shaped, adjoining window opening 158 on the top. As
shown in FIGS. 11 and 12, the apparatus 110 includes a blower 124,
an air disperser 126, a HEPA filter 128, an air delivery plenum
130, air delivery channels 132, 134 and 160, a perforated metal
sheet 154 and an air return chase 136. By way of example, the
blower 124 is rated at onetenth horsepower, 500 cubic feet per
minute when unimpaired and 275 cubic feet per minute when impaired
by a filter such as the filter 128 which causes a one-inch of
mercury static pressure differential across its two faces. The
blower 124 is supported against a divider 138 having an aperture
139 above the mouth of the blower. The disperser 126 is identical
to the disperser 26 described above and the HEPA filter 128 is
identical to the HEPA filter 228. The air delivery plenum 130
routes air, blown by the blower 124, to the channel 132, which
channel accelerates the air to approximately 600 feet per minute at
its slotted opening 148. The channel 132, as well as the slotted
opening 148, extend from the perforated sheet 154 to a roof 164 of
the cleaning apparatus 110. Hence, the channel 132 develops a
curtain of air 151, as indicated by arrows 149, which flows right
to left across the front opening of the cleaning chamber 112. The
curtain of air covers the front opening forming a barrier, and is
returned as indicated by an arrow 196 via a tapered channel 159 and
the return air chase 136.
As shown clearly in FIG. 12, the channel 134 is defined by a wall
166 which angles a way from a side wall 150 and a wall 168 which
extends vertically, and communicates with the air delivery plenum
130 by an opening 169 and with the cleaning chamber 112 by a
slotted opening 171. The walls 166 and 168 extend from a point
behind the air curtain 151 to a rearward wall 182 of the cleaning
chamber 112. The channel 160 is defined by a wall 172 which angles
away from a wall 152 and a wall 170 which extends vertically, and
communicates with the air delivery plenum by an opening 181 and
with the cleaning chamber 112 by a slotted opening 183. The walls
170 and 172 also extend from a point behind the air curtain 151 to
the rearward wall 182 of the cleaning chamber 112. By way of
example, the openings 169 and 181 are three inches wide and the
openings 171 and 183 are onefourth inch wide.
As shown in FIG. 13 when the blower 124 is activated, air is forced
upwardly through a rear portion 190 of the air delivery plenum 130
and, as indicated by an arrow 191, into the channel 134, as
indicated by an arrow 192 into the channel 160, and as indicated by
an arrow 193 into the channel 132, and accelerated within the
channels to a speed of approximately 600 feet per minute. Air
streams developed by the channels 134 and 160 are laminar when they
leave the slotted openings 171 and 183 and converge upon one
another and the foot 114, which convergence causes air turbulence
in the vicinity of the foot 114. The turbulent air, as discussed
above, and any remaining laminar air dislodge particulates from the
bootie 111. The particulates are drawn through perforations in the
plate 154, into the air return chase 136 as indicated by arrows
194,194 and rearwardly into the blower 124, and later blown into
the HEPA filter 128. The air curtain 151 prevents particulates
which avoid the air streams of the channels 134 and 160 from
escaping from the cleaning chamber into the work area through the
opening of the box. In addition, an ankle 115 of the user which
engages the heel-shaped border of the top opening blocks much of
the top opening of the cleaning chamber, and the front space
between the rear of the ankle and the front opening of the box is
acted upon by the air curtain, causing particulates located therein
to be drawn into the air return chase 136.
The apparatus 110 further includes a photoelectric eye 190 and
associated delaying circuitry which operates as does the
photoelectric eye 90 to activate the blower 124 once the foot is
inserted and to de-activate the blower 124 a few seconds after the
foot is withdrawn.
FIG. 14 illustrates a cleaning system generally designated 308
embodying the invention, which system comprises endless, movable
conveyor chains 317,317, tracks 349,349 which supports the chains
317,317, timing pulleys 311,311 which support the chains, a DC
motor 315 for driving the timing pulleys, clamps 313,313 for
hanging wipes 314,314, loose gloves, loose booties, or other limp
or rigid objects from the chains 317,317, a cleaning apparatus 310,
including a blower 324 (FIG. 16) for cleaning the wipes 314,314
carried by the clamps 313,313, and a controller 319 for activating
the motor 315 and the blower 324 according to a routine. The
cleaning apparatus 310 includes a cleaning chamber 312 extending
laterally from one side 330 to an opposite side 332, an entrance
window opening 316 of the cleaning chamber 312 through which the
wipes 314,314 enter the cleaning chamber and an exit window opening
318 of the cleaning chamber through which the wipes exit the
cleaning chamber after being cleaned.
As shown more clearly in FIG. 16, the blower 324 is located in a
rear compartment of the apparatus 310, and the apparatus 310
further comprises a diffuser 326 located above the blower, a HEPA
filter 328 located above the diffuser and spaced a few inches
therefrom, an air delivery plenum 330 leading forwardly from the
HEPA filter, tapered channels 331, 332, 334, 360, 362 and 364 (FIG.
15) which direct and accelerate air from the air delivery plenum
into the cleaning chamber 312, and an air return chase 336 leading
back to the blower 324.
The blower 324 is identical to the blower 24, the mouth of the
blower 324 abuts a directs 338, and the diffuser 326 is supported
on the other side of the perforated sheet adjacent the mouth of the
blower. The diffuser 326 is identical to the diffuser 26 and serves
to disperse air about the bottom of the HEPA filter 328 which
filter 328 is identical to the HEPA filter 28 and is mounted to a
rectangular filter frame 340. As indicated by an arrow 341, air
proceeds upwardly from the blower 324, through the disperser 326
and through the HEPA filter 328 and then forwardly through the air
delivery plenum 330. Then, the air proceeds downwardly through the
tapered channels 331, 332, 334, 360, 362 and 364. In a manner
analogous to the development of the curtain 51 of air in the
cleaning apparatus 10, the channels 331 and 332 develop curtains of
air which cover the entrance window 316 and the exit window 318,
respectively. In addition, the tapered channels 334 and 360 develop
streams of air which converge upon one another and upon the wipes
314,314 indicated as a located within the cleaning chamber, and the
tapered channels 362 and 364 develop streams of air which converge
upon one another and upon the wipes 314a,314a. The convergence
causes turbulence in the air streams, which turbulence facilitates
the removal of particulates from the wipes. The air of the air
curtains and the air of the air streams is returned via
perforations in the sheet 354 and the return air chase 336, drawn
back into the blower 324 and forced through the filter 328 where
they are trapped.
To prevent the air curtains from dislodging particulates from the
wipes 314,314 as the wipes pass through the windows 316 and 318,
the controller 319 shuts off the blower 324 when it directs the
motor 315 to advances the chains 317,317 and the wipes 314,314 they
carry into the cleaning chamber 312. After, the chains advance the
length of the cleaning chamber 312 and a new group of contaminated
wipes 314,314 indicated as b are moved into the cleaning chamber
312, the controller 319 de-activates the motor 315 and activates
the blower 324 to clean the wipes. After a sufficient cleaning time
has elapsed, the controller again shuts off the blower 324 and
directs the motor 315 to advance the chains 317,317 another such
length to move the newly-cleaned wipes 314b,314b through the exit
window 318 and beyond the apparatus 310.
FIG. 17 shows another embodiment of the invention generally
designated 410, which embodiment is specially adapted to clean
wipes 414,414, loose gloves, loose booties, and other limp
articles. Except as noted below, the cleaning apparatus 410 is
identical to the cleaning apparatus 10 and comprises identically
referenced components. The cleaning apparatus 410 further includes
a perforated drum 411 supported for rotation within the cleaning
chamber 12, a motor 414 which turns the drum 411, an ON/OFF switch
429 which replaces the photoelectric eyes 90,90 and associated
delay circuitry, and a timer 430. The drum 411 comprises a front
rim 416, a rear rim 418 and a cylindrical grid 420 of wires
supported between the two rims.
To clean the wipes 414,414, an operator manually places them in the
drum 411 and activates the motor 414 and the blower 24 with the
ON/OFF switch 429. Consequently, the wipes 414,414 are tumbled and
agitated by the rotation of the drum 411 and struck by the air
streams developed by the channels 34, 60, 62 and 64, the forces of
the drum agitation and the air streams dislodging particulates from
the wipes 414,414. The dislodged particulates are drawn through the
grid 420 of wires, the end openings of the drum 411 and the
perforations in the sheet 54 and into the air return chase 36, the
air curtain 51 insuring that dislodged particulates do not escape
from the cleaning apparatus 410 into the work environment. Next,
the blower 24 receives the contaminated air and forces it through
the HEPA filter 28 trapping the previously dislodged particulates.
The timer 430 automatically shuts off the blower 24 and the motor
414 after a predetermined cycle cleaning time.
By the foregoing, cleaning apparatuses for removing particulates
from objects have been disclosed. However, numerous modifications
and substitutions may be made without deviating from the scope of
the invention. For example, if desired for simplicity in
construction, the electronic eyes 90,90 and the cleaning apparatus
10 may be omitted and the blower 24 operating continuously
throughout a workday. Also, if desired, additional channels may be
located within the cleaning apparatuses 10, 210, or 310, which
additional channels direct streams of air from right to left or
from left to right within the respective cleaning chambers and
occur in pairs, the channels of each pair directing their streams
of air upon each other and the object to be cleaned. In addition,
one or more shelves may be installed within the cleaning chamber 12
to support objects to be cleaned. Therefore, the invention has been
disclosed by way of illustration and not by way of limitation.
* * * * *